The distribution of angioarchitectural changes within the vicinity of the arteriovenous crossing in branch retinal vein occlusion

Longitudinal Assessment of the Choroidal Vascularity Index in Eyes with Branch Retinal Vein Occlusion-Associated Cystoid Macular Edema

INTRODUCTION

Cystoid macular edema (CME) is the most common cause of central vision loss in eyes with branch retinal vein occlusion (BRVO eyes). In recent literature, choroidal vascularity index (CVI) has been proposed to be an enhanced depth imaging optical coherence tomography (EDI-OCT) metric that may help characterize choroidal vascular changes in the setting of retinal ischemia, and potentially prognose visual outcomes and treatment patterns for patients with BRVO-related CME. This study sought to further characterize choroidal vascular changes in BRVO by comparing the CVI, subfoveal choroidal thickness (SFCT), and central subfield thickness (CST) in BRVO eyes with CME compared to unaffected fellow eyes.

METHODS

This was a retrospective cohort study. Subjects included treatment-naïve BRVO eyes with CME diagnosed within 3 months of onset of symptoms and unaffected fellow eyes. EDI-OCT images were collected at baseline and at the 12-month follow-up visit. CVI, SFCT, and CST were measured. Demographics, treatment patterns, and best-corrected visual acuity (VA) were abstracted. Median CVI, SFCT, CST, and VA were compared between the two cohorts. Longitudinal relationships between these variables were analyzed.

RESULTS

A total of 52 treatment-naïve eyes with BRVO and CME and 48 unaffected fellow eyes were identified. Baseline CVI was lower in eyes with BRVO than in fellow eyes (64.7% vs. 66.4%, P = 0.003). At 12 months, there was no difference in CVI between BRVO eyes and fellow eyes (65.7% vs 65.8%, P = 0.536). In BRVO eyes, there was a strong correlation between reduced CST and improved VA over the 12-month study period (r = 0.671, P < 0.001).

CONCLUSION

There are differences in CVI in treatment-naïve BRVO eyes with CME at presentation compared to fellow eyes, but these differences resolve over time. Anatomic changes in macular thickness in BRVO eyes with CME may be correlated with VA outcomes.

Multimodal evaluation of hemorrhages within intraretinal cystoid spaces in a blood-fluid level presentation

INTRODUCTION

We describe characteristic findings on multimodal evaluation and the features of hemorrhage within a foveal cystoid space in a patient presenting cystoid macular edema secondary to Branch Retinal Vein Occlusion (BRVO).

CASE DESCRIPTION

We report a case of a 64-year-old diabetic male patient presenting gradual blurry vision in the left eye. Fundoscopic findings were suggestive of BRVO, such as hard exudates and mild venous engorgement superotemporally and diffuse macular intraretinal hemorrhages. In the foveal area, there was cystoid edema with blood-fluid level (BFL) inside one of the cystoid spaces. Retina multimodal evaluation, including color, blue filter, and red-free fundus photography, fluorescein angiography, fundus autofluorescence, and spectral-domain optical coherence tomography (SD-OCT) B and C scan imaging, confirmed blood within foveal cystoid space. The patient underwent antiangiogenic therapy with significant improvement of macular edema and reduction of the cystoid space after 3 months. In addition, there was a resolution of visual symptoms. The cystoid space previously partially filled with blood, persisted, despite presenting smaller volume and medium reflectivity in the SD-OCT.

CONCLUSIONS

Multimodal evaluation of blood-fluid level within foveal cystoid space in patients with BRVO has not been described previously. Identification of this sign may support the diagnosis of retinal vein occlusion in doubtful cases and further studies must be carried out to establish if the presence of BFL correlates with visual outcomes.

Therapeutic Effects of Combination Therapy and Photobiomodulation Therapy on Retinal Regeneration

Introduction: Many systemic and ocular diseases cause macular edema (ME). Macular edema is seen in two primary forms; the first is diffuse thickening of the macula, and the other is a macula with a distinct petaloid (cloverleaf) appearance called cystoid macular edema. Macular edema has a known role in the reduction of visual equity, and many options have been proposed for the reversal of this condition. Methods: Articles on the effects of macular laser grid photocoagulation on diabetic macular edema (DME) or cystoid macular edema published between 2000 and 2022 were collected from PubMed, Google Scholar, and Web of Science. The following keywords were used for the search: "macular laser photocoagulation", "macular edema", "cystoid macular edema", "intravitreal pharmacotherapies", and "antivascular endothelial growth factor". Two hundred nineteen articles were found in google scholar and 165 articles in PubMed, and a total of 58 articles were included in the study after applying the exclusion criteria. Results: We investigated the effects of various lasers photocoagulation such as Focal and/or grid macular laser, subthreshold micropulse laser (SMPL), as well as intravitreal pharmacotherapies with triamcinolone acetonide, and fluocinolone, and extended released intraocular implants such as Ozurdex, Retisert, Iluvien, and anti-vascular endothelial growth factors such as bevacizumab (Avastin), Eyela, and Lucentis. Corticosteroids were more effective than lasers, although some researchers have found that lasers and combined lasers and corticosteroids are more effective. In addition, some studies have shown that the frequency and concentrations of intravitreal pharmacotherapies are effective in increasing visual outcomes. Conclusion: The results of the studies showed that the combined intravitreal corticosteroids are much more effective in improving visual acuity (VA) than a single corticosteroid, and the low concentration of the drug is safer. Still, corticosteroids have side effects such as increased intraocular pressure and glaucoma. Therefore, combining the medication with a laser is much more reasonable than each alone. Also, the subthreshold photocoagulation laser (670 nm) is better at reducing the central macular thickness (CMT) and improving VA than the micro pulse yellow laser and pan-retinal photocoagulation (PRP).

Early menopause is associated with increased risk of retinal vascular occlusions: a nationwide cohort study

This nationwide population-based cohort study evaluated the association between female reproductive factors and the incidence of retinal vein occlusion (RVO) and retinal artery occlusion (RAO) using data provided by the Korea National Health Insurance Service. A total of 2,289,347 postmenopausal women over 50 years of age who participated in both national health screening and cancer screening in 2013 or 2014 were included. Data on female reproductive factors, including age at menarche, age at menopause, parity, history of hormone replacement therapy, and oral contraceptive pill usage, were collected. Patients were followed up until December 2018, and incident cases of RVO and RAO were identified using registered diagnostic codes from claim data. During an average follow-up period of 4.90 years, 7461 and 1603 patients were newly diagnosed with RVO and RAO, respectively. In the multivariable-adjusted Cox proportional hazard model, patients who experienced menopause after 55 years of age had a lower risk of RVO and RAO development compared to those who had menopause before 45 years of age, with a hazard ratio (95% confidence interval) of 0.83 (0.76–0.95) for RVO and 0.80 (0.66‒0.98) for RAO. In conclusion, early menopause was an independent risk factor for future development of RVO and RAO.

Angiographic Risk Features of Branch Retinal Vein Occlusion Onset as Determined by Optical Coherence Tomography Angiography

Purpose

Examine associations between the vasculature at arteriovenous (AV) crossings and the onset of branch retinal vein occlusion (BRVO).

Methods

We included 78 patients with major BRVO, 35 patients with macular BRVO, and 110 controls without BRVO and determined the vessel positions at AV crossings, where the first- or second-order branches of the retinal veins associate, using a viewing angle of 12 × 12 mm² in optical coherence tomography angiography (OCTA).

Results

We reviewed 1349 and 1276 AV crossings in BRVO patients and control subjects, respectively. The proportions of venous overcrossing were 26.5%, 28.6%, and 26.8% at non-causative crossings in BRVO eyes, non-BRVO fellow eyes, and unaffected control eyes, respectively; however, the rate of venous overcrossings at the causative crossings was 45.1%. In OCTA analyses, we divided the branches into macular- or non-macular veins. The rate of venous overcrossing was 52.5% at causative crossings in major BRVO but was 28.6% in macular BRVO. Odds ratios for whether venous overcrossing was a risk factor for BRVO were 3.09 (95% confidence interval [CI], 1.96–4.88) and 0.94 (95% CI, 0.44–2.00) for non-macular veins and macular veins, respectively. The patients with major BRVO caused by venous overcrossing were younger than patients for whom the cause was arterial overcrossing (P < 0.001). The onset of macular BRVO did not differ between crossing patterns at causative crossings (P = 0.60).

Conclusions

In eyes with BRVO, venous overcrossing was a common angiographic feature at causative crossings and might be a risk factor for major BRVO onset.

Guidelines for the Management of Retinal Vein Occlusion by the European Society of Retina Specialists (EURETINA)

The high prevalence of cardiovascular disease particularly in the elderly population is associated with retinal vascular disease. Retinal vein occlusions represent severe disturbances of the hypoxia-sensitive neurosensory retina. Acute and excessive leakage leads to the diagnostic hallmarks of retinal hemorrhage and edema with substantial retinal thickening. Advanced diagnostic tools such as OCT angiography allow to evaluate retinal ischemia and identify the risk for late complications and will soon reach clinical routine besides fluorescein angiography. Accordingly, the duration of non-perfusion is a crucial prognostic factor requiring timely therapeutic intervention. With immediate inhibition of vascular leakage, anti-VEGF substances excel as treatment of choice. Multiple clinical trials with optimal potential for functional benefit or a lesser regenerative spectrum have evaluated aflibercept, ranibizumab, and bevacizumab. As retinal vein occlusion is a chronic disease, long-term monitoring should be individualized to combine maintenance with practicability. While steroids may be considered in patients with systemic cardiovascular risk, surgery remains advisable only for very few patients. Destructive laser treatment is an option if reliable monitoring is not feasible. Ophthalmologists are also advised to perform a basic systemic workup to recognize systemic concomitants. The current edition of the EURETINA guidelines highlights the state-of-the-art recommendations based on the literature and expert opinions in retinal vein occlusion.

Arteriovenous crossing associated with branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is defined as the focal occlusion of a first or second-order branch of retinal vein, which occurs most frequently at an arteriovenous (AV) crossing. Direct ophthalmoscopy, color fundus photography, and fluorescein angiography facilitate observation of AV crossings parallel to the retinal plane. Optical coherence tomography (OCT), with its high-depth resolution, enables observation of retinal lesions perpendicular to the retinal plane. OCT angiography (OCTA) provides depth-resolved images of the retinal vasculature by segmenting three-dimensional data. In this review, we discuss novel findings related to affected AV crossings associated with BRVO obtained via OCT and OCTA. The high-depth resolution of OCT or OCTA is useful for observation of the narrowed vein and determination of the vessel position of the affected AV crossing. Studies using OCT and OCTA have shown that BRVO caused by a venous overcrossing is more prevalent than previously reported, and that venous narrowing was significantly greater in instances caused by a venous overcrossing than in those caused by an arterial overcrossing. Moreover, OCTA also revealed that the retinal nonperfusion area size was larger in eyes with BRVO caused by a venous overcrossing than in those with BRVO caused by an arterial overcrossing. This contrasts with earlier findings obtained by conventional imaging modalities predating OCT, which showed that an arterial overcrossing was more common than a venous overcrossing at the causative venous occlusion site in eyes with BRVO. This review discusses these findings and their significance in the study of AV crossing associated with BRVO.

BRANCH RETINAL VEIN OCCLUSION SECONDARY TO A RETINAL ARTERIOLAR MACROANEURYSM: A NOVEL MECHANISM SUPPORTED BY MULTIMODAL IMAGING

BACKGROUND/PURPOSE

To report a case of a branch retinal vein occlusion secondary to a retinal arteriolar macroaneurysm (RAM).

METHODS

Retrospective case report describing examination findings, treatment outcome and unique multimodal imaging features demonstrated on fluorescein angiography, optical coherence tomography, optical coherence tomography angiography and adaptive optics photography of the retinal vessels and RAM.

RESULTS

A 61-year-old man presented with 20/200 vision in the right eye because of a branch retinal vein occlusion secondary to a RAM. After sector panretinal photocoagulation and a course of 24 intravitreal antivascular endothelial growth factor injections over 4 years, visual acuity improved to 20/25. Fluorescein angiography showed filling of the RAM even after 4 years. Optical coherence tomography angiography demonstrated venous collateral vessels in both the superficial and deep capillary plexuses, and adaptive optics imaging revealed a gap between the RAM wall and occluded vein.

CONCLUSION

Multimodal imaging of this unusual presentation illustrated a novel mechanism of branch retinal vein occlusion in which a primary RAM adjacent to the junction of two retinal veins led to obstruction of venous flow without evidence of direct compression. This supports the theory that perianeurysmal microenvironment changes may be of importance in the pathogenesis of venous occlusion.

Comparative Study of Vitrectomy with and without Vein Decompression for Branch Retinal Vein Occlusion: A Pilot Study

Purpose

To report the clinical outcomes in patients undergoing pars plana vitrectomy with and without vein decompression for treatment of branch retinal vein occlusion (BRVO).

METHODS

Thirty-five eyes with macular edema and visual acuity worse than 20/100 secondary to BRVO were prospectively evaluated. Vitrectomy with posterior hyaloid removal and vein decompression at the arteriovenous crossing was performed on 15 eyes (Group 1); consecutively, the same technique without vein decompression was performed on 20 eyes (Group 2). Primary outcome was visual acuity and secondary outcomes were resolution of macular edema and development of neovascularization.

Results

No differences were found between groups in either patient age (p=0.566) or preoperative visual acuity (p=0.505). No differences were found in visual acuity at 3 (p=0.651), 6 (p =0.697), 9 (p =0.763), 12 (p=0.881), or 18 (p=0.748) months. Mean time for macular edema resolution and visual acuity improvement was 9 months in both groups, with a mean improvement of 3.5 ± 2.35 lines in Group 1 and 3.2 ± 2.97 lines in Group 2. No eyes in either group developed new vessels.

CONCLUSIONS

Results suggest that vitrectomy with posterior hyaloid removal without vein decompression can resolve macular edema, improve vision, and prevent development of new vessels in BRVO.

Morphologic and Functional Retinal Vessel Changes in Branch Retinal Vein Occlusion: An Optical Coherence Tomography Angiography Study

PURPOSE

The present study aimed to investigate the morphology of the retinal vasculature in eyes with branch retinal vein occlusion (BRVO) using optical coherence tomography (OCT) angiography.

DESIGN

Observational case series.

METHODS

Fluorescein angiography (FA) and OCT angiography were used to examine macular area and the retinal vasculature at the affected arteriovenous (AV) crossing in 46 patients with BRVO.

RESULTS

FA revealed that the affected AV crossing pattern involved arterial overcrossing in 23 eyes (50.0%) and venous overcrossing in 11 eyes (23.9%). However, FA failed to detect the crossing pattern in 10 eyes (21.7%). OCT angiography was significantly more effective for identification of the AV crossing pattern than FA (44 eyes; 95.7%; P = .013). The number of eyes with venous overcrossing detected via OCT angiography (20 eyes, 43.5%) was also higher than that detected via FA (P = .047). OCT angiography revealed that venous narrowing (25.5 ± 21.1 μm) was significantly greater in instances of venous overcrossing than in those of arterial overcrossing (46.4 ± 23.7 μm, P = .005). Macular nonperfusion areas (NPAs) were larger in eyes with venous overcrossing than in those with arterial overcrossing (P = .011 for superficial plexus, P = .049 for deep plexus). The peripheral NPA was significantly larger in eyes with venous overcrossing (65.1 ± 35.3 disc area [DA]) than in those with arterial overcrossing (17.2 ± 24.1 DA; P < .001).

CONCLUSIONS

Our findings suggest that BRVO characterized by venous overcrossing may be more prevalent than previously reported, and that there is a significant association between NPA size and AV crossing pattern.

Health care claims for primary open-angle glaucoma and retinal vein occlusion from an 11-year nationwide dataset

To evaluate the risk of retinal vein occlusion (RVO) development after primary open-angle glaucoma (POAG) and the risk of POAG development after RVO, we conducted a nationwide, population-based 11-year longitudinal study. National registry data were collected from the Korean National Health Insurance Research Database, comparing 1 025 340 (~2.2%) subjects who were selected from 46 605 433 Korean residents in 2002. Each sampled patients was tracked until 2013. POAG developed in 0.92% of the RVO group (n = 6 826) and in 0.22% of the comparison group. RVO developed in 0.99% of the POAG group (n = 4 138) and in 0.37% of the comparison group. RVO was associated with an increased risk of POAG development (hazard ratio [HR], 3.25; 95% confidence interval [CI], 2.39–4.42) and POAG was associated with an increased risk of RVO development (HR, 5.05; 95% CI, 3.94–6.47). Comorbidity of systemic hypertension and diabetes mellitus further increased the risk of POAG development in the RVO group (HR, 3.58 and HR, 5.98, respectively). Patients with RVO exhibit a significantly higher risk of POAG development and patients with POAG exhibit a significantly higher risk of RVO development, based on an 11-year follow-up period.

Spectral-Domain Optical Coherence Tomography Angiography of Central Retinal Artery Occlusion

The authors report the use of optical coherence tomography angiography (OCTA) to determine retinal blood flow in a patient with central retinal artery occlusion (CRAO). Spectral-domain OCTA (SD-OCTA) was performed on an eye with CRAO. En face vascular images were constructed using an optical microangiography algorithm. The retinal vasculature was clearly imaged with high fidelity; areas of perfused retina were identified with exquisite detail. This study supports use of OCTA in diagnosing and monitoring CRAOs. Future research is warranted to recognize full potential of this imaging modality. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:467-470.].

Glaucoma Progression in the Unaffected Fellow Eye of Glaucoma Patients Who Developed Unilateral Branch Retinal Vein Occlusion

PURPOSE

To investigate glaucoma progression in eyes with glaucoma that developed unilateral branch retinal vein occlusion (BRVO) in the contralateral eye.

DESIGN

Retrospective, case-control study.

METHODS

Participants: Forty glaucoma patients with unilateral BRVO and 40 age- and baseline mean deviation (MD) of the visual field (VF)-matched glaucoma patients were evaluated during at least 4 years of follow-up.

OBSERVATION PROCEDURES

Glaucoma progression was defined as VF progression using the modified Anderson criteria of the MD of the VF. Kaplan-Meier life table analyses were performed to compare times to confirmed VF progression, and related risk factors were evaluated using the Cox proportional hazards model.

MAIN OUTCOME MEASURES

VF progression.

RESULTS

Comparison of the baseline characteristics between the glaucomatous eyes that developed BRVO and the contralateral glaucomatous eyes that did not develop BRVO showed that BRVO occurred in the more advanced-stage eyes. Patients with glaucoma with BRVO in the fellow eyes had significant and frequent detection of disc hemorrhage (35.0%), which was 7.5% in patients with glaucoma without BRVO (P = .003). Four (10%) patients from the glaucoma group without BRVO and 22 (55.0%) patients from the glaucoma group with BRVO in the fellow eye showed progression according to the modified Anderson criteria (P < .001). Disc hemorrhage and the presence of BRVO in the fellow eye were found to be significantly predictive of VF progression using the Cox proportional hazards model.

CONCLUSIONS

More advanced glaucomatous eyes develop BRVO. Patients who developed BRVO showed more rapid glaucoma progression in the contralateral eyes without BRVO compared with glaucoma patients who did not develop BRVO.

Microaneurysms cause refractory macular edema in branch retinal vein occlusion

Intravitreal anti-vascular endothelial growth factor (VEGF) agents can treat macular edema (ME) in branch retinal vein occlusion (BRVO). However, refractory ME, the mechanism of which is not well elucidated, occurs frequently. Sixty-six eyes with ME secondary to BRVO were enrolled in this retrospective observational case-control study. Twenty eyes received a sub-Tenon’s capsule injection of triamcinolone acetonide (STTA), 22 eyes an intravitreal anti-VEGF injection (ranibizumab), 16 eyes were switched from STTA to ranibizumab, 4 eyes underwent vitrectomy, and 4 eyes were untreated. Multiple regression analysis and multivariate logistic regression analysis were conducted, respectively, to identify independent predictors of visual acuity (VA) prognosis and risk factors for refractory ME longer than 1 year. The mechanism of refractory ME and therapeutic approaches for identified risk factors also were investigated. Thirty-four (52%) eyes had refractory ME for over 1 year. Microaneurysms were identified as risk factors for refractory ME, leading to poor final VA. Ranibizumab suppressed microaneurysm formation and refractory ME, with early administration more effective. For already formed microaneurysms, laser photocoagulation reduced additional treatments. Microaneurysms may cause refractory ME in BRVO. Alternative therapy to suppress microaneurysms should be considered to prevent refractory ME in patients with BRVO.

Microvascular Abnormalities on Optical Coherence Tomography Angiography in Macular Edema Associated With Branch Retinal Vein Occlusion

PURPOSE

To determine the ability of optical coherence tomography (OCT) angiography to image the microvascular structures compared with fluorescein angiography (FA) in patients with macular edema associated with branch retinal vein occlusion (BRVO).

DESIGN

Retrospective, observational, consecutive case series.

METHODS

Twenty-eight eyes of 27 patients (14 men, 13 women; mean age, 68.4 years) with macular edema associated with BRVO were enrolled. Simultaneous OCT angiography and FA were performed in all patients to evaluate the microvascular abnormalities and nonperfused areas.

RESULTS

OCT angiography detected nonperfused areas in 28 eyes and FA in 18 eyes. The respective findings of superficial capillary telangiectasias by OCT angiography and FA were 13 and 11 eyes, for deep capillary telangiectasias 28 eyes and 11 eyes, for collateral vessels 18 eyes and 16 eyes, and for microaneurysms 13 eyes and 14 eyes. OCT angiography facilitated differential layer analysis of microaneurysms and collaterals as well as capillary telangiectasias in the retina.

CONCLUSIONS

OCT angiography can visualize microvascular abnormalities equally well or better than FA in eyes with BRVO. Multimodal imaging using OCT angiography and FA can be a powerful tool to evaluate the pathology in BRVO.

Long-term outcome after vitrectomy for macular edema with retinal vein occlusion dividing into the occlusion site

Purpose. To investigate the efficacy of treatment for macular edema secondary to retinal vein occlusion (RVO) with vitrectomy. Methods. This retrospective study identified patients with macular edema associated with RVO between January 2004 and April 2006. Inclusion criteria were eyes with (1) preoperative visual acuity (VA) of 20/40 or worse, (2) a central foveal thickness (CFT) greater than 250 μm, and (3) vitrectomy with internal limiting membrane and intravitreal triamcinolone acetonide. Each patient had their RVO classified as a major or macular BRVO or hemispheric RVO (HSRVO). Results. Forty-six eyes with major BRVO, 18 eyes with macular BRVO, and 17 eyes with HSRVO were investigated. VA was significantly improved at 24 months after surgery for each group (P < 0.05). Vision in the macular BRVO group 24 months after surgery was significantly better than that in other groups (P < 0.05). For each group, a concomitant reduction of CFT was noted at every time point when compared to preoperative values (P < 0.001). Conclusions. In macular BRVO, the postoperative vision 24 months after surgery was significantly better than the other groups. These findings suggest that additional and earlier treatments might be more important for patients with major BRVO and HSRVO than for those with macular BRVO.

Matched control study of visual outcomes after arteriovenous sheathotomy for branch retinal vein occlusion

Background

The purpose of this study was to evaluate visual outcomes of arteriovenous sheathotomy for macular edema due to branch retinal vein occlusion (BRVO).

Methods

The medical records of 45 eyes from 45 patients who had undergone vitrectomy surgery with arteriovenous sheathotomy for BRVO were studied. Forty-five eyes of 45 patients with a BRVO but without intervention were studied as the control group. The best-corrected visual acuity and central macular thickness were compared between the two groups at baseline and at 1, 3, 6, and 12 months postoperatively.

Results

Improvement of best-corrected visual acuity was 0.42 logarithm of the minimum angle of resolution (logMAR) units in the sheathotomy group and 0.22 logMAR units in the control group (P=0.007). The mean postoperative central macular thickness was significantly thinner in the sheathotomy group at 1 month (P=0.01), but not at 3, 6, and 12 months (P=0.75, P=0.81, and P=0.46, respectively). Improvement of best-corrected visual acuity at 12 months was significantly correlated with baseline best-corrected visual acuity, age, duration of symptoms, and sheathotomy (P<0.05).

Conclusion

Arteriovenous sheathotomy for BRVO improves best-corrected visual acuity significantly more than the natural course of the BRVO disease process.

LRG1 promotes angiogenesis by modulating endothelial TGF-β signalling

Aberrant neovascularization contributes to diseases such as cancer, blindness and atherosclerosis, and is the consequence of inappropriate angiogenic signalling. Although many regulators of pathogenic angiogenesis have been identified, our understanding of this process is incomplete. Here we explore the transcriptome of retinal microvessels isolated from mouse models of retinal disease that exhibit vascular pathology, and uncover an upregulated gene, leucine-rich alpha-2-glycoprotein 1 (Lrg1), of previously unknown function. We show that in the presence of transforming growth factor-β1 (TGF-β1), LRG1 is mitogenic to endothelial cells and promotes angiogenesis. Mice lacking Lrg1 develop a mild retinal vascular phenotype but exhibit a significant reduction in pathological ocular angiogenesis. LRG1 binds directly to the TGF-β accessory receptor endoglin, which, in the presence of TGF-β1, results in promotion of the pro-angiogenic Smad1/5/8 signalling pathway. LRG1 antibody blockade inhibits this switch and attenuates angiogenesis. These studies reveal a new regulator of angiogenesis that mediates its effect by modulating TGF-β signalling.

Morphologic and functional changes in retinal vessels associated with branch retinal vein occlusion

OBJECTIVE

To study the morphologic and functional changes in retinal veins of eyes affected with branch retinal vein occlusion (BRVO) by thin sectioning with optical coherence tomography (OCT).

DESIGN

Prospective, observational, cross-sectional study.

PARTICIPANTS

Twenty-five consecutive patients (25 eyes) with acute BRVO.

METHODS

Major retinal veins, arteries, and arteriovenous (A/V) crossing were examined by sequential thin sectioning by Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany). The retinal blood flow was mimicked in vitro and scanned with Spectralis HRA+OCT.

MAIN OUTCOME MEASURES

Morphologic characteristics of normal and BRVO-affected retinal vessels seen in OCT sections.

RESULTS

Cross-sectional OCT images revealed physiologic retinal vessels as oval configurations with 4 distinctive hyperreflectivities in a line. The vessel walls showed the innermost and outermost hyperreflectivity, and the blood flow showed internal paired hyperreflectivities with an hourglass shape. No eye with disturbed blood flow due to BRVO showed this internal hyperreflectivity pattern. In vitro, OCT sections of the blood within the glass tube without flow showed homogeneous reflectivities. Increased blood flow velocity resulted in the development of heterogeneous internal reflectivity and hourglass-shaped hyperreflectivities. In all eyes with acute BRVO, sequential sectioning with OCT visualized 3-dimensional vascular architecture and the intravascular conditions at the A/V crossing. At the affected A/V crossing, arterial overcrossing was seen in 17 eyes and venous overcrossing was seen in 8 eyes. In eyes with arterial overcrossing, the retinal vein seemed to run deep under the artery at the A/V crossing, and the venous lumen often appeared to be preserved even at the A/V crossing. In all eyes with venous overcrossing, the retinal vein appeared to be compressed and choked between the internal limiting membrane and the arterial wall at the A/V crossing. Optical coherence tomography sectioning showed intravenous thrombi in 21 eyes, and the thrombi were detected downstream of the A/V crossing in all the cases. The detection of thrombus was significantly associated with ischemic pattern in BRVO (P=0.036).

CONCLUSIONS

In eyes with BRVO, sequential thin sections with OCT visualized 3-dimensional retinal vasculature. The present OCT findings suggest that BRVO may occur by 2 different mechanisms, depending on the relative anatomic positions of the crossing vessels.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Retinal vein occlusion: beyond the acute event

Retinal vein occlusion is a major cause of vision loss. We provide an overview of the clinical features, pathogenesis, natural history, and management of both branch retinal vein occlusion and central retinal vein occlusion. Several recent multicenter randomized clinical trials have been completed which have changed the approach to this disorder. Management of retinal vein occlusions can be directed at the underlying etiology or the resulting sequelae. Options include surgical intervention, laser photocoagulation, intravitreal pharmacotherapy, and sustained drug delivery devices.

Retinal vein occlusions: The potential impact of a dysregulation of the retinal veins

A retinal vein occlusion (RVO) is a sight threatening disease. It can be divided into central vein occlusion and branch retinal vein occlusion. The pathogenesis of the condition remains to be solved. Mechanical compression of the vessel wall or thrombotic occlusion of the vessel lumen, sometimes combined with rheological disorders, are often assumed pathomechanisms. Accordingly, the therapy relies either on mechanical decompression, lyses of thrombi or improvement of rheology. A number of observations however, such as the relationship of RVO to atherosclerotic risk factors, spontaneous reversibility particularly in young patients, rest flow observed in angiography, occlusion despite anticoagulation or thrombocytopenia and finally the positive effect of anti-VEGF therapy are not explained by the present pathogenetic concept. As a new concept we propose a local venous constriction induced by vasoconstrictive molecules diffusing from neighbouring diseased arteries and/or from other neighbouring (hypoxic) tissues. Recognizing these postulated conditions might lead to an earlier identification of impending vein occlusions as well as to a treatment more tailored to the risk factor constellation of the particular patient.

Recurrence of hemispheric retinal vein occlusion

The purpose of this article is to report a case in which a double hemispheric retinal vein occlusion (HSRVO) occurred in the same eye, involving firstly the superior half and later the inferior half of the retina. A 63-year-old woman with ill-controlled hypertension had been diagnosed with central retinal vein occlusion in the right eye in January 1998. The patient had a HSRVO of the superior hemiretina in November 2003, and a HSRVO of the inferior hemiretina in August 2005. The patient underwent a complete work-up, but the only detected risk factor was hypertension. Bearing in mind the absence of an effective treatment able to reduce both the incidence and the recurrence of retinal vein occlusion, detection and control of the risk factors, such as hypertension, is essential. We should make every effort to improve the compliance of our patients in controlling general diseases all their lives.

Interventions for branch retinal vein occlusion: an evidence-based systematic review

TOPIC

To assess the evidence on interventions to improve visual acuity (VA) and to treat macular edema and/or neovascularization secondary to branch retinal vein occlusion (BRVO).

CLINICAL RELEVANCE

Branch retinal vein occlusion is the second most common retinal vascular disease.

METHODS/LITERATURE REVIEWED

English and non-English articles were retrieved using a keyword search of Medline (1966 onwards), Embase, the Cochrane Collaboration, the National Institute of Health Clinical Trials Database, and the Association for Research in Vision and Ophthalmology Annual Meeting Abstract Database (2003-2005). This was supplemented by hand searching references of review articles. Two investigators independently identified all randomized clinical trials (RCTs) with more than 3 months' follow-up.

RESULTS

From 4332 citations retrieved, 12 RCTs were identified. There were 5 RCTs on laser photocoagulation. Grid macular laser photocoagulation was effective in improving VA in 1 large multicenter RCT, the Branch Vein Occlusion Study (BVOS), but 2 smaller RCTs found no significant difference. The BVOS showed that scatter retinal laser photocoagulation was effective in preventing neovascularization and vitreous hemorrhage in patients with neovascularization, but a subsequent RCT found no significant effect. Randomized clinical trials evaluating intravitreal steroids (n = 2), hemodilution (n = 3), ticlopidine (n = 1), and troxerutin (n = 1) showed limited or no benefit.

CONCLUSIONS

There is limited level I evidence for any interventions for BRVO. The BVOS showed that macular grid laser photocoagulation is an effective treatment for macular edema and improves vision in eyes with VA of 20/40 to 20/200, and that scatter laser photocoagulation can effectively treat neovascularization. The effectiveness of many new treatments is unsupported by current evidence.

Long-term outcomes of vitrectomy with or without arteriovenous sheathotomy in branch retinal vein occlusion

PURPOSE

To evaluate the long-term effect of vitrectomy with or without arteriovenous sheathotomy for macular edema secondary to branch retinal vein occlusion (BRVO).

METHODS

The study was a prospective, randomized, comparative, interventional case series of 36 patients (36 eyes) who underwent pars plana vitrectomy with or without arteriovenous sheathotomy for macular edema due to BRVO of <or=8 weeks' duration of symptoms. Eighteen eyes with arteriovenous sheathotomy (sheathotomy group) were compared with 18 eyes without sheathotomy (vitrectomy group). Main outcomes measures were best-corrected visual acuity and central foveal thickness as evaluated by optical coherence tomography.

RESULTS

Baseline demographic characteristics of the groups were similar. Postoperative follow-up period ranged from 12 months to 45 months (31 months). Median best-corrected visual acuity significantly improved from 0.4 at baseline to 1.0 at the final visit in both groups, and there was no significant difference in best-corrected visual acuity at any postoperative period between the groups. Of 16 patients with duration of symptoms of <4 weeks, those with arteriovenous sheathotomy had a tendency toward better visual outcomes than those without arteriovenous sheathotomy (P = 0.064). The central foveal thickness also significantly decreased after surgery in both groups, but the differences were not significant for the two groups at each time point. No patients had severe intraoperative and/or postoperative complications.

CONCLUSIONS

Our findings suggest that vitrectomy with or without arteriovenous sheathotomy may improve the long-term functional and tomographic outcomes for patients with macular edema secondary to BRVO. Although additional arteriovenous sheathotomy did not lead to a distinct functional benefit in this series, early surgical intervention may result in better visual outcomes.

Arteriovenous adventitial sheathotomy for branch retinal vein occlusion: report of a case with longterm follow-up

PURPOSE

To report the longterm follow-up of a case of branch retinal vein occlusion (BRVO) treated with vitrectomy and adventitial sheathotomy.

METHODS

A three-port vitrectomy was performed in a 55-year-old man with symptoms of BRVO of about 3 months' duration. After a core vitrectomy, the adventitial sheath of the affected arteriovenous crossing was dissected so that the anterior surface of the arteriole was freely exposed.

RESULTS

On the second postoperative day, visual acuity (VA) in the affected left eye had increased from preoperative 0.3 to 0.6. Within 6 months the fundus had almost normalized and vision improved to 1.0. Cataract surgery was performed about 2 years after the vitrectomy. At a follow-up 4 years and 11 months after the sheathotomy, VA was 1.0 and no signs of recurrence were seen.

CONCLUSIONS

Adventitial sheathotomy may improve vision in selected cases of BRVO. Further studies are necessary to determine the role of sheathotomy in the management of cases with BRVO.

Evaluation of arteriovenous crossing sheathotomy for decompression of branch retinal vein occlusion

PURPOSE

To report the effects of arteriovenous adventitial sheathotomy on anatomical and functional improvements in patients with macular oedema due to branch retinal vein occlusion (BRVO).

METHODS

Pars plana vitrectomy and arteriovenous sheathotomy was performed on 11 patients with BRVO who had vision loss due to macular oedema. Ten patients with macular oedema due to BRVO and who have been treated with grid laser photocoagulation were included in the control group. The measurement of visual acuity with ETDRS chart was taken preoperatively and at 1, 3, 6, and 9 months follow-up in the study group and at 1, 3, 6, and 9 months after grid laser in the control group.

RESULTS

The mean preoperative logMAR visual acuity was 0.84+/-0.3 in the surgical group and 1.06+/-0.4 in the control group. The postoperative mean logMAR visual acuity was 0.41+/-0.2, 0.40+/-0.2, 0.40+/-0.3, and 0.36+/-0.3 at 1, 3, 6, and 9 months follow-up, respectively. In the control group the postlaser mean logMAR visual acuity was 0.92+/-0.3, 0.87+/-0.4, 0.85+/-0.3, and 0.82+/-0.3 at 1, 3, 6, and 9 months follow-up, respectively. The improvements of visual acuity in both groups were statistically significant when compared to pretreatment (P=0.003 and P=0.007 at 9 months in the study and control group, respectively).

CONCLUSION

Arteriovenous sheathotomy for decompression of BRVO in patients who have vision loss due to macular oedema was safe and effective for anatomical and functional improvement and resulted in significantly better visual outcomes than a matched control group of laser-treated eyes.

Arterio-venous dissection after isovolaemic haemodilution in branch retinal vein occlusion: a non-randomised prospective study

PURPOSE

The rationale for this pilot study was to add arterio-venous dissection (AVD) after unsuccessful medical treatment in a well-defined group of patients with branch retinal vein occlusion (BRVO).

METHODS

In this prospective, interventional case series 35 consecutive patients with a visual acuity (VA) of 0.4 (logMar) or worse were scheduled for surgery within the first 3 months of the onset of BRVO. The study endpoint was VA 1 year after AVD. Secondary study endpoints were: correlation of VA and successful vessel dissection; complication rate; and number of additional surgical procedures within the first year of AVD.

RESULTS

Preoperative VA (logMar) was 0.82+/-0.05 (range 0.2-1.6). VA 6 weeks postoperatively was 0.54+/-0.06 (range 0-1.6), 3 months postoperatively 0.61+/-0.07 (0-1.56), 6 months postoperatively 0.74+/-0.08 (range 0-2) and 12 months postoperatively 0.55+/-0.07 (range 0.1-1.5). VA improved 1 year after AVD (p=0.0004). An improvement in VA did not depend on successful separation of the artery and the vein. Four patients had a retinal detachment, 19 patients needed cataract surgery within the first year of AVD. A total of 24 additional surgical procedures were needed.

CONCLUSIONS

Patients with BRVO may profit from AVD compared with a historical control group. Visual improvement was found irrespective of the successful dissection of vessels. The cataract formation rate and additional surgery was a shortcoming of the AVD procedure.

Transvitreal limited arteriovenous-crossing manipulation without vitrectomy for complicated branch retinal vein occlusion using 25-gauge instrumentation

PURPOSE

To evaluate a new technique, 25-gauge transvitreal limited arteriovenous-crossing manipulation without vitrectomy (LAM), for the treatment of branch retinal vein occlusion (BRVO) complicated by macular hemorrhage and/or macular edema recalcitrant to grid laser photocoagulation.

METHODS

Twelve eyes of 12 patients underwent LAM for BRVO performed by a single surgeon (M.S.H.) using the 25-gauge nitinol flexible-extendable blunt pick. The presence or absence of intraoperative reperfusion visualization, pre- and postoperative visual acuity, macular thickness as measured by optical coherence tomography, intraocular pressure, and lens status were evaluated.

RESULTS

Restoration of blood flow was noted in all patients and was based on intraoperative reestablishment of a red column of erythrocytes through the previously closed vessel. Mean visual acuity improved from 20/200 (logarithm of the minimal angle of resolution [LogMAR] +/- SD, 1.00 +/- 0.32) preoperatively to 20/70 (LogMAR +/- SD, 0.56 +/- 0.28) (P = 0.0003) at the final visit. Eleven (92%) of 12 eyes had >or=2 lines of visual improvement. Five eyes (45%) had final visual acuity of 20/50 or better. Mean macular thickness +/- SD improved from 401.0 +/- 73.2 to 178.7 +/- 19.6 microm (P < 0.0001) at the final visit. No statistically significant difference was noted in cataract progression or intraocular pressure. Mean follow-up +/- SD was 49.9 +/- 19.6 weeks. All patients were observed for at least 12 weeks.

CONCLUSION

LAM may achieve outcomes comparable with those of arteriovenous adventitial sheathotomy for complicated BRVO.

Angiographic findings in arteriovenous dissection (sheathotomy) for decompression of branch retinal vein occlusion

BACKGROUND

Arteriovenous dissection (sheathotomy) is a new therapeutic option in patients with branch retinal vein occlusion (BRVO) and macular involvement. We present an angiographic follow-up of 22 patients who underwent arteriovenous dissection (AVD).

METHODS

Twenty-two patients (15 women; mean age 68.7+/-8.0 years) were examined preoperatively and 6 weeks, 3 months, 6 months, and 1 year after AVD. For assessment of retinal hemodynamics, arteriovenous passage time (AVP) of the affected and unaffected branches at first (AVPe) and at maximal (AVPmax) venous filling were measured. Changes in the foveal avascular zone (FAZ) were calculated to determine foveal structural changes. Visual acuity was assessed as functional parameter.

RESULTS

The early AVP (AVPe) of the affected branch increased from 4.4+/-0.8 s preoperatively to 4.9+/-0.6 s 6 weeks after surgery and decreased to 2.7+/-0.4 s 1 year after surgery (p=0.05). When compared to the unaffected control branch, AVPe was significantly increased in the affected branch preoperatively (4.5+/-0.8 s versus 1.5+/-0.2 s, p<0.01), 6 weeks (4.9+/-0.6 s versus 2.1+/-0.3 s, p<0.01), 3 months (2.7+/-0.4 s versus 1.5+/-0.2 s, p<0.01), and 6 months (3.1+/-0.4 s versus 2.2+/-0.3 s, p=0.02) after AVD. After 1 year, AVPe no longer differed between the affected and the control branch (2.7+/-0.4 s versus 2.6+/- 0.3 s). AVPmax was significantly increased in the affected branch preoperatively (11.8+/-0.8 s versus 7.7+/-1.0 s, p<0.05). The AVPmax in the affected branch with the exception of 3 months after surgery (10.2+/-1.1 s, p<0.01) was no longer elevated when compared to preoperative values. The area of the FAZ did not change significantly but showed a trend for enlargement.

CONCLUSION

AVD for decompression of BRVO leads to a significant decrease of AVP and may ameliorate retinal perfusion in the affected branch.

Vitrectomy with or without arteriovenous adventitial sheathotomy for macular edema associated with branch retinal vein occlusion

PURPOSE

compare the results of vitrectomy with or without arteriovenous (AV) crossing sheathotomy for macular edema associated with branch retinal vein occlusion (BRVO).

DESIGN

Interventional case series.

METHODS

A retrospective study of 36 eyes with BRVO-associated macular edema. Twenty eyes underwent AV sheathotomy (AS group), and 16 eyes underwent posterior vitreous detachment (PVD group). Best-corrected visual acuity (BCVA), fluorescein angiography (FA), and optical coherence tomography to determine foveal thickness were conducted preoperatively and at 12 months postoperatively.

RESULTS

The mean postoperative BCVAs were significantly better in both the AS and the PVD group (P = .008 and P = .001, respectively). Foveal thickness decreased significantly 1 month after surgery in both groups (P = .002 and P = .007) and continued to decrease up to 12 months. The postoperative mean BCVA and improvement of BCVA and foveal thickness were not significantly different for the two groups at any postoperative period. Postoperative FA showed reperfusion of the occluded vein in 10 eyes in the AS group and 2 eyes in the PVD group, and formation of shunt vessels at the AV crossing site or around the macular region in all of the other eyes of both groups.

CONCLUSIONS

Both AV sheathotomy and simple PVD significantly reduced macular edema associated with BRVO. However, there was no significant difference in the improvement of macular function following either procedure. Postoperative improvement of retinal circulation by either reperfusion of the occluded vein or collateral vessel formation was found. This accounted for functional and morphologic improvements.

Vitrectomy with arteriovenous decompression and internal limiting membrane dissection in branch retinal vein occlusion

PURPOSE

The therapeutic armamentarium for functional improvement after branch retinal vein occlusion (BRVO) is limited with uncertain efficacy. Some surgeons have proposed surgical decompression of the vein at the arteriovenous (AV) crossing.

METHODS

Forty-three patients with BRVO were treated in the authors' department from August 1999 to April 2001 with AV decompression. Twenty-five patients with comparable BRVO who refused this surgical intervention served as a control group. All 68 patients received an isovolemic hemodilution therapy for 10 days. The surgical procedure consisted of a standard pars plana vitrectomy and separation of the overlying artery from the vein using microscissors. In 16 cases dissection of the internal limiting membrane (ILM) in the macular area and around the AV crossing was also performed. Assessment of visual acuity, fluorescein angiography, and multifocal electroretinography were performed preoperatively and 6 weeks after surgery in seven patients.

RESULTS

Surgical procedure and postoperative course were uneventful. In most of the treated eyes visual acuity improved and fluorescein angiography revealed capillary reperfusion. Functional results in patients with AV decompression were highly significantly better than in the control group. Furthermore, removal of the ILM seems to have an additional beneficial effect on the functional outcome.

CONCLUSION

These results demonstrate the therapeutic effect of surgical AV decompression in BRVO. Additional removal of the ILM seems to improve the functional results. Further experience may answer some open questions.

Vitreoretinal surgery for complications of branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is second only to diabetic retinopathy as a cause of retinal vascular disease. Vision loss from BRVO may be associated with multiple causes, including macular edema, macular ischemia, foveal hemorrhage, vitreous hemorrhage, epiretinal membrane, and retinal detachment. The few published studies that report outcomes of pars plana vitrectomy for complications of BRVO consist only of case reports and small case series, limitations of which include small sample sizes and lack of comparison groups. Given the variable outcomes among patients with untreated BRVO, comparison groups are necessary for accurate evaluation of the efficacy of pars plana vitrectomy for BRVO.

Adventitial sheathotomy for treatment of macular edema associated with branch retinal vein occlusion

Laser therapy has been shown to be of benefit in eyes with branch retinal vein obstruction. More recently, pars plana vitrectomy with adventitial sheathotomy has also been shown to be of benefit, particularly for those eyes with branch retinal vein obstruction and poorer vision. The technique and results of this new therapeutic modality are discussed herein.

Familial thrombophilia and retinal vein occlusion

PURPOSE

To perform a pilot study on the prevalence of familial thrombophilia in all cases of retinal vein occlusion with no known risk factors.

METHODS

Over the 1 year study period 71 patients presented with a new diagnosis of retinal vein occlusion (age 28-90 years). Fifty-five (77%) were excluded because of local predisposing factors. The remaining 16 (23%) had a full risk factor history taken and blood investigations of rheological factors and thrombophilia including tests for the factor V Leiden mutation, prothrombin G20210A allele and hyper-homocystinemia.

RESULTS

Of those with no local predisposing factors, 3 patients had antiphospholipid antibodies, 3 had raised fibrinogen levels, 4 had hyper-homocystinemia and 1 was heterozygous for the Leiden mutation. Other lifestyle risk factors such as obesity, smoking and a positive family history of venous thrombosis were not uncommon. No patient had the prothrombin G20210A variant.

CONCLUSIONS

It seems likely that several risk factors, both genetic and acquired, need to be present for thrombosis to occur. In investigating a new patient with a retinal vein occlusion one should test for hypertension, glaucoma and diabetes mellitus. Estimation of plasma viscosity and a full blood count are cheap investigations which may reveal neoplasia or vasculitis, and lipid levels should be estimated. In a young patient or one with an unexpected vein occlusion and a personal or family history of thrombosis, a hypercoagulable state may rarely be identified. This additional testing should include testing for antiphospholipid antibodies and a full thrombophilia screen including the factor V Leiden mutation, homocysteine and the prothrombin variant as part of a clinical trial. Until the role of these markers in thrombosis is better defined in relation to causation of retinal vein occlusion and treatment has been shown to improve outcome, we can not recommend them for routine testing. If a hereditary defect is found, referral should be made to a hematologist and consideration given to anticoagulation and screening of family members to prevent further thrombotic episodes. Retinal vein occlusions are multifactorial in origin except in rare cases.